Corona sdk walls

Getting Started Newbie Questions
#1

I am creating a game with balls and when they drop from the screen some of them are usually off of the screen so can someone help me on how to change this ?

local function spawnBall() for i=1,numberBall do Ball = display.newCircle(100, 80, 10) physics.addBody(Ball, "dynamic", {density=.1}) Ball:setFillColor( 0.7 ) Ball:setStrokeColor( 0, 0, 5 ) Ball:applyLinearImpulse(-.05, .05, 0, 0) Ball.x = math.random(-10, 400); Ball.y = -40; transition.to( Ball, { time=math.random(2000,8000), x=math.random(-10,400) , y=600, onComplete=clearBall } ); physics.addBody( Ball, "dynamic", { density=0.1, bounce=0.1, friction=0.1, radius=0 } ); --Adding touch event end end
#2

like this?

local physics = require("physics") physics.start( ) physics.setGravity( 0, 0 ) local numberBall = 20 local scale0= ((display.actualContentWidth- display.contentWidth)\*.5)\*-1 local scale0Y= ((display.actualContentHeight- display.contentHeight)\*.5)\*-1 local function spawnBall() for i=1,numberBall do local Ball Ball = display.newCircle(100, 80, 10) physics.addBody(Ball, "dynamic", {density=.1}) Ball:setFillColor( 0.7 ) Ball:setStrokeColor( 0, 0, 5 ) Ball:applyLinearImpulse(-.05, .05, 0, 0) Ball.x = math.random(-10, 400); Ball.y = -40; transition.to( Ball, { time=math.random(2000,8000), x=math.random(scale0,display.actualContentWidth) , y=600 } ); physics.addBody( Ball, "dynamic", { density=0.1, bounce=0.1, friction=0.1, radius=0 } ); --Adding touch event end end spawnBall()
#3

That dosen’t help 

#4

How do balls should behaviour?

#5

I want them to fall down but sometimes either they go past the left wall or they spawn over the wall . I want them to fall down the screen where I can see them 

#6

1.You probably should not be using transition.to , use :applyForce or :setLinearVelocity. Transition.to may move the physics body, but is not pick up by the physics engine. 

  1. How to my example not help, Are you use letterbox? Can you post you config.lua?
#7 
application = { content = { width = 768, height = 480, scale = "letterBox", fps = 30, --[[imageSuffix = { ["@2x"] = 2, }, --]] }, --[[-- Push notifications notification = { iphone = { types = { "badge", "sound", "alert", "newsstand" } } }, --]] }
#8

Try this (work on Corona simulator Samsung Galaxy 3 720x1280, idea based on post https://forums.coronalabs.com/topic/32843-how-can-i-detect-if-a-kinematic-object-is-on-the-screen/ )

local physics = require( "physics" ) -- Default  physics.setGravity( 0,  9.8 )  local function spawnBall()     local ball = display.newCircle( 100, 80, 10 )     ball.name= "ball"     physics.addBody( ball, "dynamic", {density=0.1} )     ball:setFillColor( 0.7 ) end local function onGlobalCollision( event )     if ( event.phase == "ended" ) then        if ( event.object1.name == "ball" ) then     display.remove( event.object1 )     elseif ( event.object2.name == "ball" ) then     display.remove( event.object2 )     end     end end physics.start() local screen = display.newRect( display.contentWidth \* 0.5, display.contentHeight \* 0.5, display.contentWidth, display.contentHeight - 400 ) screen.name = "screen" physics.addBody( screen,  "static" )  screen.isSensor = true Runtime:addEventListener( "collision", onGlobalCollision ) timer.performWithDelay( 1000, spawnBall, 3 )

Read about it :slight_smile:

Physics Setup - https://docs.coronalabs.com/guide/physics/physicsSetup/index.html

Collision Handling  -  https://docs.coronalabs.com/guide/physics/collisionDetection/index.html#handling

object.isSensor - https://docs.coronalabs.com/api/type/Body/isSensor.html

Spawn enemy - https://coronalabs.com/blog/2014/11/04/tutorial-basic-spawning/

Hope this help :slight_smile:

EDIT : I add “- 400” so you see that ball disappear.

local screen = display.newRect( display.contentWidth \* 0.5, display.contentHeight \* 0.5, display.contentWidth, display.contentHeight - 400 )
#9

like this?

local physics = require("physics") physics.start( ) physics.setGravity( 0, 0 ) local numberBall = 20 local scale0= ((display.actualContentWidth- display.contentWidth)\*.5)\*-1 local scale0Y= ((display.actualContentHeight- display.contentHeight)\*.5)\*-1 local function spawnBall() for i=1,numberBall do local Ball Ball = display.newCircle(100, 80, 10) physics.addBody(Ball, "dynamic", {density=.1}) Ball:setFillColor( 0.7 ) Ball:setStrokeColor( 0, 0, 5 ) Ball:applyLinearImpulse(-.05, .05, 0, 0) Ball.x = math.random(-10, 400); Ball.y = -40; transition.to( Ball, { time=math.random(2000,8000), x=math.random(scale0,display.actualContentWidth) , y=600 } ); physics.addBody( Ball, "dynamic", { density=0.1, bounce=0.1, friction=0.1, radius=0 } ); --Adding touch event end end spawnBall()
#10

That dosen’t help 

#11

How do balls should behaviour?

#12

I want them to fall down but sometimes either they go past the left wall or they spawn over the wall . I want them to fall down the screen where I can see them 

#13

1.You probably should not be using transition.to , use :applyForce or :setLinearVelocity. Transition.to may move the physics body, but is not pick up by the physics engine. 

  1. How to my example not help, Are you use letterbox? Can you post you config.lua?
#14 
application = { content = { width = 768, height = 480, scale = "letterBox", fps = 30, --[[imageSuffix = { ["@2x"] = 2, }, --]] }, --[[-- Push notifications notification = { iphone = { types = { "badge", "sound", "alert", "newsstand" } } }, --]] }
#15

Try this (work on Corona simulator Samsung Galaxy 3 720x1280, idea based on post https://forums.coronalabs.com/topic/32843-how-can-i-detect-if-a-kinematic-object-is-on-the-screen/ )

local physics = require( "physics" ) -- Default  physics.setGravity( 0,  9.8 )  local function spawnBall()     local ball = display.newCircle( 100, 80, 10 )     ball.name= "ball"     physics.addBody( ball, "dynamic", {density=0.1} )     ball:setFillColor( 0.7 ) end local function onGlobalCollision( event )     if ( event.phase == "ended" ) then        if ( event.object1.name == "ball" ) then     display.remove( event.object1 )     elseif ( event.object2.name == "ball" ) then     display.remove( event.object2 )     end     end end physics.start() local screen = display.newRect( display.contentWidth \* 0.5, display.contentHeight \* 0.5, display.contentWidth, display.contentHeight - 400 ) screen.name = "screen" physics.addBody( screen,  "static" )  screen.isSensor = true Runtime:addEventListener( "collision", onGlobalCollision ) timer.performWithDelay( 1000, spawnBall, 3 )

Read about it :slight_smile:

Physics Setup - https://docs.coronalabs.com/guide/physics/physicsSetup/index.html

Collision Handling  -  https://docs.coronalabs.com/guide/physics/collisionDetection/index.html#handling

object.isSensor - https://docs.coronalabs.com/api/type/Body/isSensor.html

Spawn enemy - https://coronalabs.com/blog/2014/11/04/tutorial-basic-spawning/

Hope this help :slight_smile:

EDIT : I add “- 400” so you see that ball disappear.

local screen = display.newRect( display.contentWidth \* 0.5, display.contentHeight \* 0.5, display.contentWidth, display.contentHeight - 400 )